Mineral oil composition



Patented Sept. 5,

UNITED STATES PATENT OFFICE 2,357,287 mean on. comrosmon Orland M. Belt! and John J. Giammaria, Woodbury, N. J., assignors to Socony-Vacuum Oil Company, Incorporated, a corporation of New,

York

No Drawing. Application Gctober so, 1942, Serial No. 463,966

11 Claims.

This application, which is a continuation-inpart of our copending application Serial No. 353,070, filed August 17, 1940, has to do in a general way with mineral oil compositions and is more particularly related to compositions comprised of a mineral oil fraction and a minor proportion of an added ingredient which will improve such oil fractions in one or more important respects.

It is the principal object of this invention to provide addition agents for use in mineral oil fractions, such as those employed as lubricants, which are multifunctional in that a single addition agent will efl'ect improvement in the pour point and the viscosity index and will retard many of the deleteriouseffects of oxidation, etc., attending the storage and use of the oil. It is a further object of this invention to provide mineral oil compositionsthe properties of which have been improved by the incorporation therein of one or more of these novel addition agents.

In Patent No. 2,197,837, issued to one of the present joint inventors, Orland M. Reiii', there is disclosed and claimed a class of multifunctional mineral oil addition agents broadly identified as oil-miscible alkyl-substituted hydroxyaromatic carboxylic acids in which the alkyl substituent is attached to the aromatic nucleus and contains at least 20 carbon atoms. The compounds disclosed in that patent may, for purposes of description herein, be designated by the general formula R-T-OH in which T represents an aromatic nucleus, R represents at least one alkyl group of at least 20 carbon atoms, and OH and COOH are attached to the aromatic nucleus T.

The present invention is predicated upon the specifically the oil-miscible alkyl-substituted hydroxyarylaliphatic carboxylic acids and the oilmiscibl alkyl-substituted hydroxyarylcycloaliphatic carboxylic acids, when characterized by the substitution of the hydroxyl hydrogen with an inorganic acyl group of the type described above, will so improve mineral oils. The general class of organic acids contemplated for acylation to form the reaction products contemplated herein may be represented by the general formula R' ,-.cooH

wherein R and T are as described above, R represents an aliphatic or alicyclic group and n is either 0 or 1.

As contemplated herein, inorganic acyl groups of acidic metalloid elements are considered to be components, or constituents, of the acids of the non-metallic or acidic metalloid elements: phosphorus; silicon and boron. They are derived from an inorganic halide selected from the group consisting of POClz, PSCla, PNClz, P013, F015,.

BC]: and SiCl4, in the reaction of'said halide with one of the aioresaid carboxylic acids, followed by subsequent water-washing oi the reaction mixture. In the inorganic acyl groups contemplated herein, the non-metallic or acidic metalloid element-P, B or Si-is joined to various groups such as =0, :8, -OH, =N or in which T, R, R and N are as given above. As used herein, the term polyvalent inorganic acyl group describes those acyl groups present in compounds, or reaction products, containing more than one (R).COOH

group.

Hereinafter, the term "acyl group" is used synonymously with the term inorganic acyl group for all of such groups are characterized by the presence of an inorganic element, P, B or Si. And as used herein, the term "acyl (and the symbol for the same, Ac) is representative of the groups given directly below in Table I and later given in Table II, where the symbol Z represents one of the non-metallic or acidic metalloid elements P, B or Si, and Q represents oxygen the discovery that the closely related acids, or sulphur.

The inorganic acyl groups contemplated herein which are indicated in the foregoing table by the 8 1 on and are obtained in the reaction of substantially one mol of the phenol carboxylic acid and substantially one mol of a halide of a non-metallic or acidic metalloid element, and subsequent waterwashing of the reaction mixture. The organosubstituted inorganic acyl groups in which more than one of the hydroxyl hydrogens are replaced y am-coon groups, are obtained when more than one mol of the phenol carboxylic acid is reacted with one mol of a halide of the aforesaid type, followed by water-washing of the reaction mixture. Thus, the substitution or acylation of the hydroxyl hydrogen of an alkyl-substituted hydroxyaromatic (or, hydroxyarylaliphaticor hydroxyarylcycloaliphatic-i carboxylic acid may be effected by reacting the acid with the halide of a non! metallic or acidic metalloid element, and water-' washing of the reaction mixture so formed. Examples of the halides which may be used in this acylation reaction are the following: P0011, PSCla, PNClz, P013, P015, 3G1: and $1014. The compound or reaction product obtained by acylating the aforesaid organic acids represented by general Formula I may be broadly classified as an oil-miscible, substantially stable hydroxyaromatic carboxylic acid ester of an inorganic acid, which is an acid of a non-metallic or acidic metalloid element. These acylated compounds or reaction products may be represented by the general formula (R').-COOH II R- -O--Ac in which R, R, T and n have the same significanoe described above in connection with Formula I, and Ac represents an inorganic acyl group as herein defined.

Reaction products, or compounds, of the aforesaid type may be further modified in their properties to condition them for use in particular oils or under particular conditions of use by substituting the carboxyl hydrogen with a metal. Reaction products or compounds, of this type are contemplated herein as a preferred group in the general class of ester derivatives of inorganic acids and may be represented by the general formula R').-c0oM m RT0Ac wherein M represents the hydrogen equivalent of a metal and the other symbols have the same significance heretofore defined.

All of the reaction products, or compounds,

-rv I aaasmsv I contemplated herein-that is the alkylated hydroxyaromatic (or, hydroxyarylallphaticor hydroxyarylcycloaliphatic-l carboxylic acid esters of the acids 01' non-metallic or acidic metalloid elements, and the metal salts thereof-may be represented by the general formula wherein X is selected from the group consisting of hydrogen and a metal and the other symbols have the same significance defined above.

with the modified reaction products, or compounds-that is, those containing metal-which represent a preferred embodiment of the present invention, the term acyl" is necessarily broadened to include such groups as are tabulated below in Table II, in which all symbols are as hereinbefore defined.

metalsoi groups 1 to 8 inclusive of the periodic system capable of forming carboxylate salts. These metals comprise the following: the alkali metals; lithium, sodium, potassium, rubidium, and caesium; the alkaline earth group: beryllium, magnesium, calcium, strontium, and barium; the metals zinc, cadmium, mercury, scandium; the metals aluminium, gallium, indium, thallium, ti-

tanium, zirconium, cerium, thorium, germanium,

tin and lead; vanadium. columbium, and tantalum; arsenic, antimony, and bismuth; chromium, molybdenum, tungsten and uranium; rhenium, manganese, iron, cobalt and nickel; ruthenium, rhodium and palladium; osmium, iridium and platinum.

' some 0! the rare earth metals are given in the foregoing. Other rare earth metals suitable for the metal carboxylate type of compounds contemplated herein are those now commercially In the metal carboxylate type of compounds,

the selection of a metal will depend to a certain extent upon the character of the oil in which the addition agent is to be added and the conditions under which the oil is to be used. Certain metals such as lead, zinc, and tin, for example, may contribute to the oiliness characteristics of the oil. In general, it appears that any metal may be employed as the metal M in carboxylate compounds of the aforesaid type to provide valuable oil addition agents. The metals contemplated herein may be broadly classified as the 7 said, the starting materials may be the closely related alkylated hydroxyarylaliphatlc carboxylic acids and alkylated hydroxyarylcycloaliphatic carboxylic acids, the synthesis and chemical composition of which will be suggested by the detailed description of ingredients and procedures given in the foregoing patent, and is further amplified in Patent No. 2,198,275 issued to Reiff et al. on April 23, 1940.

In general, these alkylated phenol carboxylic acids maybe obtained by first alkylating a phecompounds, be predominantly comprised of high molecular weight aliphatic hydrocarbons, and since petroleum wax is a preferred source of such high molecular weight alkyl substituents, the products so alkylated are, as in the aforesaid patent, identified herein as being wax"-substituted.

Following alkylation, the alkylated phenol is converted to an alkali metal phenate, which is then carboxylated to form the alkylated phenol alkali metal carboxylate. The carboxylate is then acidified with a mineral acid to form the alkylated phenol carboxylic acid. To facilitate handling, the foregoing synthesis is carried out in mineral oil solution so that the ultimate product is a mineral oil solution of the alkylated hydroxyaromatic carboxylic acid.

In the event chlorinated paraffin wax (or a chlorinated aliphatic hydrocarbon of the type which characterizes chlorinated paraflin wax) is used as the'alkylating agent, the product obtained is referred to as wax-substituted. To further identify these wax-substituted" products, we have followed the custom employed in the aforesaid patents of using the parenthetical expression (A-B) indicating with "A" the number of atomic proportions of chlorine in the chlorinated wax reacted with one mol of phenol and indicating with B the percentage chlorine content of the chlorinated wax. Thus, wax-phenol carboxylic acid (3-16) indicates that the wax-phenol used in obtaining the acid is the product obtained by reacting one mol of phenol with a quantity of chlorinated wax (of 16% chlorine content) containing 3 atomic proportions of chlorine.

The acylation of the hydroxyl group in the aforesaid hydroxyaromatic carboxylic acid is accomplished by slowly adding the halide of a nonmetallic or acidic metalloid element to a mineral oil solution of the alkylated hydroxyaromatic acid at an elevated temperature in the neighborhood of 150 F. After such addition the mixture is heated at a temperature of about 300 F. until the reaction is complete, after which it is cooled to about 150 F., diluted with a suitable solvent such as benzol, and water-washed free of mineral acid, after which thesolvent is distilled off to obtain the finished acid ester.

In order to further describe the acylation, or substitution, procedure for the preparation of the reaction products or compounds contemplated herein, a series of reactions which are believed 76 mama? to take place are explained by the When a typical, and preferred, halide, PCls, is reacted with a typical hydroxyaromatic carboxyllc acid, wax phenol carboxylic acid (3-16) in substantially equimolecular proportions, it is believed that the carboxylic acid group is converted to the corresponding chlorcarbonyl group 1 W8X----CO0H+PC11 With water-washing, the chlorcarbonyl group in the final product of Reaction 1-2, is converted back to the carboxylic acid group o-r=o Similarly, when another typical halide, P015, is reacted with the same acid, wax phenol carboxylic acid (3--16), in substantially equimolecular proportions, it is believed that the carboxylic acid group -(H30H) O is converted to the corresponding chlorcarbonyl and the hydroxyl group is converted to the phosphoric acid dichloride group /Cl wa 6 following:

assme'r with water-washing, the chlorcarbonyl group in the final product of Reaction 1-2 is converted back to the carboxylic acid group in the :final product of Reaction 1'-2' is converted to the phosphoric acid group As aforesaid, the reaction products or compounds contemplated by the present invention are substantially free of halogen, which distinguishes the same from the subject matter of U. S. Patent No. 2,259,452 with which we are familiar. This patent is directed to mineral oil compositions comprising mineral oil fractions and aromatic ortho-phosphito carboxylic acid chlorides and derivatives thereof. As described therein such compounds or reaction products may be characterized or by the presence of a substituted carbonyl group,

wherein Y represents the organic residue of an organic compound containing a replaceable hydrogen atom or a replaceable metal atom. In the procedure of that patent the replaceable hydrogen or metal is removed in the reaction with the aromatic ortho-phosphito carboxylic acid chloride by formation of a chloride of the said hydrogen or metal atom which is released as a gas or as a precipitate. In short, compounds or reaction products described in the aforesaid patent are not characterized by the presence of a carboxyl group nor by a metal carboxylate group, as are those compounds or reaction products contemplated by the present invention, and in this regard the compounds or reaction products of the present invention distinguish over those of the aforementioned patent.

In the synthesis of compounds in which the carboxyl-hydrogen is substituted with metal, the preferred procedure is to first form the alkali metal carboxylate by reaction of the acid ester, the formation of which has been described above, with an alkali metal alcoholate. Other desired metals can then be substituted by double decomeitherhy the presenceof a' chlorcarbonyl group,

, A butyl alcohol solution of position of the alkali metal carboxylate with a normal inorganic or fatty acid salt of the desired metal.

Further details in the procedure which may be followed in synthesizing the acylated (esteriiied) reaction products or compounds contemplated herein may be obtained from the following specific examples describing the preparation of the wax-phenol carboxylic acid (3-16) ester of phosphorous acid and the metal carboxylate derivatives thereof.

In Examples I and 11 below, the acyl group (Ac) of general Formula IV is derived from PCls and probably has the group formula (Rm-000x wherein Z of the group formula of Table II is trivalent phosphorus (P EXAMPLE I Reaction mixture Grams Wax-phenol carboxylic acid (3-16) 50 Mineral oil 150 PC]: 3.34

Procedure of. the products contemplatedherein. contains phosphorus in addition to the elements carbon, hydrogen and oxygen.

. Exunms II Reaction mixture Wax-phenol carboxylic acid (3-16) ester of phosphorous acid. grams- 50 Mineral oil do.. 150 Metallic sodium do 1.68 00014 do 4.75

Butyl al P c Procedure The ester of phosphorous acid was dissolved in the butyl alcohol and the sodium added in thin strips. The reaction mixture was then heated about /2 hour at 250 F. to form the sodium salt. CoClz was slowly added. The temperature was raised to 300 F., and the alcohol was distilled. The mixture was then cooled, diluted with benzol and filtered. The solvent was distilled to obtain the finished product, the wax-phenol cobaltous carboxylate (3-16) ester of phosphorous acid.

To demonstrate the improved properties obtained in mineral oil blends containing addition agents of the type discussed herein, we have conducted several comparative tests with representative minerol oils alone and with the same oils blended with these improving agents. The results of these tests are disclosed in the following examples.

Pour point depressant action stock of 120 seconds Saybolt viscosity at 210 F., and the conditions observed were:

a. The extent to which the piston rings were stuck;

These tests were conducted 'with a motor oil The extent t0 which the Oil rings w e fi d having a Saybolt Universal viscosity of 6'7 secwith p onds at210 F. and a, pour point of +20 F, Th c. The amount of carbonaceous deposit in the pour points of blends formed from this oil and and representative agylated wax-phenol carboxylic d. The neutralization number or acidity (N. N.) acids and metal carboxylates of the type conof the templated herein are listed m Table m below The results obtained in these tests are set forth from which it will be observed that these reaction m Table V below. wherein s 1 and A: reprepmducts or compounds, t esters of jncrganic sent the oil alone; oil 13; represents the same oil acids of non-metallic or acidic metalloid elements containmg 1% 0f the Wax-Phenol carboxylic acid are highly efiective pour point depressant (Ii-16) ester of phosphorous acid, and oil B3 is the same as oil A: with /2% of the wax-phenol TABLE III cobaltous carboxylate (316) ester of phosphoric acid. Addition agent Per cent bgi g I TABLE v Wax-phenol carboxylic acid (3-16) ester F. mug

of phosphorous acid 54 Wax-phenol eobaltous carboxylate (3-16) Percent Grams s U ester of Dmsphomus M Oil Degrees stuck slots arb n N N i Wax-phenol vanadyl carboxylate (3-16) filled deposit 210? ester of phosphorous acid m 5 wax-phenokostannous carboxylate (3-16) ester or ph sphoi-ous acid M 20 1 2 3 4 5 3 4 5 Wax-plhenol carboxylic acid (3-16) ester oip osphoric acid 54 Z) iv a i plze ng l c g igtgig gg b v M .3. 273 36? 36 0 368 36g 7 5 7 12.5 1.7 141.6 ei-n v acii'Ci-l'fi'fie'iof 3 11:11:: 180 o 360 180 so 75 75 111 4 ii) iii; 511mm 9 54 40 B1 0 0 0 0 0 0 0 o 4.0 2.9 5.

Viscosity index improvement Corrosion inhibition The data listed in Table v below showing the In order to demonstrate the effectiveness of effectiveness f the addition agents contemplated the mineral oil addition agents of the present herein for improving viscosity index were obtained in the conventional manner from the Saybolt viscosity of the oil and the oil blends at 100 F. and 210 F. The oil used was a viscous mineral oil of the lubricant type.

TABLE IV S. U. viscosity Improving agent Percent by wt.

100 F. 210" F. V. I.

None 140.7 41.8 79.3 Wax-phenol carboxylic acids- 16) ester of phosphorous aci 1 152.1 42.8 87.0 Wax-phenol cobaltous carboxylate (3-16) ester of phosphorous acid 1 154.9 43.0 87.5 Waxhenol vanadyl oai'boxylate (3-16) ester of phosphorous aci 1 153.7 42.9 86.9 Wax-phenol carboxylic acid (3-16 ester of phosphoric acid. 1 153. 7 12.9 86.9 Wax-p enol cobaltous carboxy late (3-16) ester of phosphoric ac 1 153.9 43. 1 91.4 Wax-phenol carboxylic acid (3-16) ester 01 silicic acid 1 152.8 42.9 88. 4

Operation test made comparative tests between an oil rid an oil blend containing representative imp oving agents of the type contemplated herein to etermine comparative behavior of the unblended oil and the improved oil under actual operating conditions. The tests were carried out in a single cylinder C. F. R. engine operated continuously over a time interval of 28 hours with the cooling medium held at a temperature of about 390 F. and the oil temperature held at a temperature of about 150 F. The engine was operated at a speed of 1200 R. P. M.

The oil used in the test was a lubricating oil In addition to the foregoing tests we has: also said Patent No. 2,197,837, a mineral oil blank and typical mineral oil blends were subjected to the following corrosion test. One typical mineral oil blend contained a representative product of the present invention-wax-phenol carboxylic acid (3-44) ester of phosphorous acid (phosphorus content, 1.62%); the other blend contained a representative product of the aforesaid patentwax-phenol carboxylic acid (3-14).

The test involved placing in a test tube a weighed section of a metal bearing and a 30 gram sample of the oil, or oil blend, and heating the oil sample to about 175 C. for 22 hours while bubbling a stream of air at the rate of 2 liters per hour against the surface of the bearing. The height of the oil in the test tube is maintained at a constant level, thus any oil lost by evaporation is replaced by additional oil. The weight loss in milligrams of the bearing is taken as the measure of the corrosiveness of the oil, or oil blend. The oil used in each test run was a mineral oil having an A. P. I. gravity of 31.4 and a Saybolt Universal viscosity at 311.4 seconds at F. The results of these tests are given below in Table VI.

TABLE VI PH cent Addition agent .dded

None Wax-phenol carboxylic acid 3-14 Waxhenol carboxylic acid (3-14 ester of p osphorous acid From the foregoing test results, it will be Seen that the acylated compound (B) is much more in the final oil composition. The esters of inorganic acids of non-metallic or acidic metalloid elements as described hereinabove may be used in amounts ranging from 4% to about and in general compositions of the desired improved properties may be obtained with amounts in the neighborhood of 1%.

We claim:

1. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible, substantially stable ester of an inorganic acid of an acidic metalloid element selected from the group consisting of phosphorus, silicon and boron, and of an organic hydroxy compound selected from the group consisting of an alkyl-substituted hydroxyaromatic carboxylic acid, an alkyl-substituted hydroxyarylaliphatic carboxylic acid, and an alkyl-substituted hydroxyarylcycloaliphatic carboxylic acid, in which the carboxyl hydrogen is substituted with metal and in which the alkyl substituent is attached to the aromatic nucleus and contains at least carbon atoms.

2. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible substantially stable ester of an inorganic acid of an acidic metalloid element selected from the group consisting of phosphorus, silicon and boron, and of an organic hydroxy compound selected from the group consisting of an alkyl-substituted hydroxyaromatic carboxylic acid, an alkyl-substituted hydroxyarylaliphatic carboxylic acid, and an alkyl-substituted hydroxarylcycloaliphatic carboxylic acid, in which the carboxyl hydrogen is substituted with metal and in which the alkyl substituent is attached to the aromatic nucleus, said alkyl substituent being an aliphatic .group of the type which characterizes petroleum wax.

3. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a wax-substituted phenol carboxylic acid ester of phosphoric acid.

4. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a wax-substituted phenol carboxylic acid ester of phosphoric acid in which ester the carboxyl hydrogen has been substituted with metal.

5. An improved mineral oil composition comprising a mineral oil having admixed therewith which it is blended and the properties desired a minor proportion of a wax-phenol carboxylic acid ester of silicic acid.

6. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a wax-substituted phenol carboxylic acid ester of silicic acid in which ester the carboxyl hydrogen has been substituted with metal.

'7. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible, substantially stable ester of a phosphoric acid, and of an organic hydroxy compound selected from the group consisting of an alkyl-substituted hydroxy aromatic carboxylic acid, an alkyl-substituted hydroxyarylaliphatic carboxylic acid and an alkyl-substituted hydroxyarylcycloaliphatic carboxylic acid, in which the alkyl substituent is attached to the aromatic nucleus and contains at least 20 carbon atoms.

8. An improved mineral'oil composition comprising a mineral oil having admixed therewith a minorproportion of an oil-miscible, substantially stable ester of a phosphoric acid, and of an organic hydroxy compound selected from the group consisting of an alkyl-substituted hydroxyaromatic carboxylic acid, an alkyl-substituted hydroxyarylaliphatic carboxylic acid, and an alkylsubstituted hydroxyarylcycloaliphatic carboxylic acid, in which the alkyl substituent is attached to the aromatic nucleus, said alkyl substituent being an aliphatic group of the type which characterizes petroleum wax.

9. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible, substantially stable ester of an acid of phosphorus, and of an organic hydroxy compound selected from the group consisting of an alkyl-substituted hydroxyaromatic carboxylic acid, an alkyl-substituted hydroxyarylaliphatic carboxylic acid, and an alkyl-substituted hydroxyarylcycloaliphatic carboxylic acid, in which the carboxyl hydrogen v is substituted with metal and in which the alkyl substituent is attached to the aromatic nucleus and contains at least 20 carbon atoms.

' 10. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a wax-substituted phenol carboxylic acid ester of boric acid.

11. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a wax-substituted phenol carboxylic'acid ester of boric acid in which ester the carboxyl hydrogen has been substituted with metal.

QRLAND M. REIFF.

JOHN J. GIALJMARIA. 

